Various forms of dolls are known into which a liquid may be introduced. Some such dolls have reservoirs for storing small quantities of such liquids. Generally, liquids stored by such dolls are used for ancilliary purposes such as hydraulically activating appendages; or duplicating bodily functions such as blood circulation, drinking or wetting; or for internal heating. Liquids in such dolls are often of such small volume relative to the volume of the doll taken as a whole, that they have little influence on the overall weight, density or "feel" of the dolls.
A type of doll having a liquid-filled resevoir that substantially fills the doll's torso is described in my co-pending patent application, Ser. No. 06/587,942, filed Mar. 9, 1984.
A problem of dolls having liquid storage resevoirs is that the reservoirs often rupture, particularly at their liquid fill ports, as a result of abusive treatment by young children who typically play with such dolls.
Another problem of dolls that have liquid storage reservoirs is that the liquid fill ports of such dolls are often permanently closed by the dolls' manufacturers so that liquid cannot be added to or removed from the reservoir after manufacture.